1 files changed, 42 insertions, 0 deletions
diff --git a/libraries/base/System/CPUTime/Posix/RUsage.hsc b/libraries/base/System/CPUTime/Posix/RUsage.hsc
new file mode 100644
index 0000000000..b59422709a
--- /dev/null
+++ b/libraries/base/System/CPUTime/Posix/RUsage.hsc
@@ -0,0 +1,42 @@
+{-# LANGUAGE CPP, CApiFFI, NumDecimals #-}
+
+#include "HsFFI.h"
+#include "HsBaseConfig.h"
+
+module System.CPUTime.Posix.RUsage
+    ( getCPUTime
+    , getCpuTimePrecision
+    ) where
+
+import Data.Ratio
+import Foreign
+import Foreign.C
+import System.CPUTime.Utils
+
+-- For struct rusage
+#if HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+
+getCPUTime :: IO Integer
+getCPUTime = allocaBytes (#const sizeof(struct rusage)) $ \ p_rusage -> do
+    throwErrnoIfMinus1_ "getrusage" $ getrusage (#const RUSAGE_SELF) p_rusage
+
+    let ru_utime = (#ptr struct rusage, ru_utime) p_rusage
+    let ru_stime = (#ptr struct rusage, ru_stime) p_rusage
+    u_sec  <- (#peek struct timeval,tv_sec)  ru_utime :: IO CTime
+    u_usec <- (#peek struct timeval,tv_usec) ru_utime :: IO CSUSeconds
+    s_sec  <- (#peek struct timeval,tv_sec)  ru_stime :: IO CTime
+    s_usec <- (#peek struct timeval,tv_usec) ru_stime :: IO CSUSeconds
+    let usec = cTimeToInteger u_sec * 1e6 + csuSecondsToInteger u_usec +
+               cTimeToInteger s_sec * 1e6 + csuSecondsToInteger s_usec
+    return (usec * 1e6)
+
+type CRUsage = ()
+foreign import capi unsafe "HsBase.h getrusage" getrusage :: CInt -> Ptr CRUsage -> IO CInt
+
+getCpuTimePrecision :: IO Integer
+getCpuTimePrecision =
+    return $ round ((1e12::Integer) % fromIntegral clk_tck)
+
+foreign import ccall unsafe clk_tck :: CLong